Investments (Tables)

3 Months Ended

Mar. 31, 2018

Investments [Abstract]

Aggregate Carrying And Approximate Market Values Of Available-For-Sale Securities

The amortized cost and estimated fair values of the Company's securities are shown in the following table (in thousands):

	March 31, 2018								December 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Securities available-for-sale:
U.S. Treasuries and U.S.
government agencies	$	1	$	—	$	—	$	1	$	2	$	—	$	—	$	2
Obligations of states and
political subdivisions	94,474		709		1,010		94,173		94,552		2,051		407		96,196
Mortgage-backed securities:
U.S. government agencies	442,044		462		15,112		427,394		425,559		1,093		7,305		419,347
Private label	599		3		—		602		649		3		—		652
Trust preferred securities	4,767		26		—		4,793		4,764		26		54		4,736
Corporate securities(1)	17,102		98		—		17,200		21,916		475		123		22,268
Total Debt Securities	558,987		1,298		16,122		544,163		547,442		3,648		7,889		543,201
Marketable equity  securities	—		—		—		—		2,136		3,563		—		5,699
Investment funds	1,525		—		60		1,465		1,525		—		36		1,489
Total Securities
Available-for-Sale	$	560,512	$	1,298	$	16,182	$	545,628	$	551,103	$	7,211	$	7,925	$	550,389

Aggregate Carrying And Approximate Market Values Of Held-To-Maturity Securities

Securities held-to-maturity:
Mortgage-backed securities:
U.S. government agencies	$	58,277	$	88	$	219	$	58,146	$	60,449	$	1,222	$	25	$	61,646
Trust preferred securities	4,000		—		—		4,000		4,000		—		—		4,000
Total Securities
Held-to-Maturity	$	62,277	$	88	$	219	$	62,146	$	64,449	$	1,222	$	25	$	65,646

Aggregate Carrying And Approximate Market Values of Marketable and Non-Marketable Securities

Other investment securities:
Non-marketable equity securities	$	11,581	$	—	$	—	$	11,581	$	14,147	$	—	$	—	$	14,147
Marketable equity securities(1)	6,947		—		—		10,584		—		—		—		—
Total Other Investment
Securities	$	18,528	$	—	$	—	$	22,165	$	14,147	$	—	$	—	$	14,147
(1) Effective January 1, 2018, the Company's equity and perpetual preferred securities are measured at fair value through net income.

Gross Unrealized Losses And Fair Value Of Investments

The following table shows the gross unrealized losses and fair value of the Company’s investments aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands):

	March 31, 2018
	Less Than Twelve Months				Twelve Months or Greater				Total
	Estimated Fair Value		Unrealized Loss		Estimated Fair Value		Unrealized Loss		Estimated Fair Value		Unrealized Loss
Securities available-for-sale:
Obligations of states and political subdivisions	$	24,204	$	211	$	18,955	$	799	$	43,159	$	1,010
Mortgage-backed securities:
U.S. Government agencies	266,824		7,208		134,047		7,904		400,871		15,112
Corporate securities	—		—		—		—		—		—
Investment funds	1,500		60		—		—		1,500		60
Total available-for-sale	$	292,528	$	7,479	$	153,002	$	8,703	$	445,530	$	16,182
Securities held-to-maturity:
Mortgage-backed securities
U.S. Government Agencies	$	39,433	$	219	$	—	$	—	$	39,433	$	219
Total held-to-maturity	$	39,433	$	219	$	—	$	—	$	39,433	$	219

	December 31, 2017
	Less Than Twelve Months				Twelve Months or Greater				Total
	Estimated Fair Value		Unrealized Loss		Estimated Fair Value		Unrealized Loss		Estimated Fair Value		Unrealized Loss
Securities available-for-sale:
Obligations of states and political subdivisions	$	4,913	$	28	$	19,440	$	379	$	24,353	$	407
Mortgage-backed securities:
U.S. Government agencies	172,807		1,887		140,226		5,418		313,033		7,305
Trust preferred securities	4,475		54		—		—		4,475		54
Corporate securities	3,357		49		2,350		74		5,707		123
Investment funds	1,500		36		—		—		1,500		36
Total available-for-sale	$	187,052	$	2,054	$	162,016	$	5,871	$	349,068	$	7,925
Securities held-to-maturity
Mortgage-backed securities
U.S. Government agencies	$	7,182	$	25	$	—	$	—	$	7,182	$	25
Total held-to-maturity	$	7,182	$	25	$	—	$	—	$	7,182	$	25

Amortized Cost And Estimated Fair Value Of Debt Securities By Contractual Maturity

The amortized cost and estimated fair value of debt securities at March 31, 2018, by contractual maturity, are shown in the following table (in thousands).  Expected maturities will differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties.  Mortgage-backed securities have been allocated to their respective maturity groupings based on their contractual maturity.

	Amortized Cost		Estimated Fair Value
Securities Available-for-Sale
Due in one year or less	$	2,715	$	2,715
Due after one year through five years	13,888		13,850
Due after five years through ten years	76,197		73,698
Due after ten years	470,998		458,604
Total	$	563,798	$	548,867
Securities Held-to-Maturity
Due in one year or less	$	—	$	—
Due after one year through five years	—		—
Due after five years through ten years	—		—
Due after ten years	62,277		62,146
Total	$	62,277	$	62,146

Gross Gains And Losses Realized

Gross gains and gross losses realized by the Company from investment security transactions are summarized in the table below (in thousands).

	Three months ended March 31,
	2018		2017
Equity and perpetual preferred security unrealized gains recognized	$	180	$	—
Gross realized gains on securities sold	—		4,276
Gross realized losses on securities sold	—		—
Net investment security gains	$	—	$	4,276